It has been almost thee years since Eugene McCarthy's stunning victory in the New Hampshire Democratic primary, but as he walked into a small meeting room at the Parker House yesterday morning, he seemed to have changed very little.

Still the soft-spoken, fatherly figure, McCarthy rekindled his venom for the war in Southeast Asia and for the internal composition of the Democratic Party in his first meeting with the press since retiring from the Senate last month.

He also refused to discount the possibility of another shot at the Presidency in 1972. "I certainly have not said I wouldn't be a peace party or third party candidate," McCarthy said. He admitted, though, that he would prefer to run as the Democratic Party candidate.

"There is the factor of traditional party loyalty and, of course, the Democratic Party is still a useful instrument in winning an election."

McCarthy said he decided not to seek reelection because he felt he could "participate more freely in political ac-tion if [he was] not in the Senate." By seeking another term in Congress, he would have been "obligated to my constituency, to the daily work of a Senator, and to the Democratic Party."

So McCarthy was at Harvard last night. Tonight he will speak at another teach-in at Brown. Later this week he will be at Notre Dame.

But the electricity which followed McCarthy during his 1968 campaign and for a long time thereafter seemed missing at yesterday morning's press conference.

Empty seats were conspicuous in the back of the room. Questioning was low-key and reserved. Marty Peretz, one of the organizers of the Harvard teach-in, talked quietly with Mass Pax leader Jerome Grossman about Sunday night's fire at the Civil Liberties legal aid office.

McCarthy expressed no surprise at the U. S. invasion of Laos. It is a U. S. invasion, he said, because while the ground troops may be South Vietnamese, the air power is American. "Bombing is an invasion-flying and dropping bombs is an invasion."

He assailed "what is essentially the arrogance of the Nixon administration in ignoring the Constitution and ignoring Congress to widen the war in Southeast Asia." An invasion of North Vietnam would necessarily concern China, McCarthy said, and "the significant chances of Chinese involvement would be greatly strengthened."

"Out of the tactics of the Laotian invasion has grown a political position based on military superiority," he said. "Johnson was trying to win a military victory and so is Nixon. Only the method is different."

"Johnson said in effect, 'I'll stop bombing if you come to the conference table.' Nixon has almost said, 'I'll start bombing unless you agree to what we want at the conference table.'"

McCarthy said Vietnamization will probably fail as a program, but "more important is the ideology which goes into it."

There was a needle, too, for the Democrats. "There have to be quantitative procedural changes within the party before we can establish a party position. Then candidates may represent the party itself; now candidates emerge independently and say, 'I'm the savior of the party' when there's not much to save."

"We have to be prepared for some kind of outside effort in 1972 if we can't change the Democratic Party internally," McCarthy said.

Although he did not announce his candidacy, McCarthy appeared to be plotting his campaign already: a crammed speaking schedule, freeing himself for political action, outspoken criticism of the war and the apparent candidates for the Democratic nomination in 1972.

Somewhere along the line, though, the novelty was lost.